Non-Solid Explosives for Shaped Charges. Part III. Metal Liner Devices Used in Explosive Ordnance Disposal Operations

Disposal of time-expired and unexploded ordnance has proved problematical in the past because of the procedures adopted; i.e., attach an explosive charge and cause the munition to function or long-range projectile attack. Improvements used explosively driven metallic liners to impact on the munition but detonation occurred with the standard plastic explosive fillings. If the munition can be persuaded to burn or at worst deflagrate, then the region of collateral damage could be reduced, even though the extended detonation safety zone would still be required. This article describes some work performed on the initiation of munitions ranging from simulated mortar shells, filled with plastic explosive PE4, via NATO standard 81-mm mortar shells to 1000-lb (450-kg) bombs by either copper cone or dish liners devices filled with various sensitized nitromethane formulations. Most of these formulations initiated deflagrations in the attacked munitions. Detonations resulted in some cases when plastic explosive, PE 4, or chemically (DETA) sensitized NM was used as the device filling. The results were analyzed in terms of the critical rate of energy delivery. Both heat dose and blast overpressure produced by the deflagrations were measured and indicated that the region of collateral damage would be extensively reduced even though the safety exclusion zone, based on full detonation, would have to be maintained. Use of these fillings would reduce the hazard to the operator during EOD work.